Actual laser speed


#1

Is the actual laser speed same as what is mentioned in Cura? If not, then is there a proper relation to get the exact laser speed?


#3

the actual moving speed is about 4 times of the speed in Cura (the gcode)

@peopolysupport


#4

From my experience the factor is ~5:

This values were measured with firmware 1.16 (i think) and xy-speed set to 4.

Feedrate [mm/s] Laser speed [mm/s]
1.7 29.9
3.3 26.6
5.0 27.3
6.7 31.7
8.3 40.1
10.0 50.2
11.7 58.3
16.7 86.4
20.0 99.1
33.3 160.5
40.0 198.8
50.0 235.0
53.3 271.5
66.7 314.6
80.0 402.4
83.3 403.9
100.0 501.8
116.7 581.7
160.0 820.2
320.0 1651.0

#5

Is it 4 times the speed mentioned in Cura or 4 times the speed in gcode?

For ex: a speed of 5mm/s mentioned in cura is mentioned as F300 in gcode.
(the speed mentioned in Cura gets multiplied by 60 when it appears in gcode.)

The confusion is whether the actual laser scan speed is calculated by,
5 mm/s x 4 = 20mm/s

                                                         or is it             300  x 4     =  1200mm/s     ???

#6

The feedrate in the Cura gui is in mm/s, the feedrate in the gcode is mm/min. For example: 85 mm/s feedrate in Cura gui = 5100 mm/min in the gcode file.


#7

Thanks!! Didn’t know that.

In the graph that you posted, is ‘Feedrate’ the value value we give in Cura?
Did you get these values yourself?


#8

Feedrate in the graph is in mm/s, so yes it’s the value you see in Cura.

I measured this values like this:

  • Slice stl of a box in cura
  • Edit gcode file so that in one layer only one feedrate is used (same feedrate for drawing and traveling).
  • Record a video of the moai printing the gcode. I put a paper in the vat to have a better image of the laser spot.
  • After printing measure the time for each layer from laser on to laser off.
  • Integrate the travel length of the layer in the gcode file, i used a python script for that.
  • Laser speed=Travel length/layer print time